package com.simtek.simplayer.utils;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.CharArrayWriter;
import java.io.Closeable;
import java.io.EOFException;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Reader;
import java.io.StringWriter;
import java.io.UnsupportedEncodingException;
import java.io.Writer;
import java.net.HttpURLConnection;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.URI;
import java.net.URL;
import java.net.URLConnection;
import java.nio.channels.Selector;
import java.nio.charset.Charset;
import java.nio.charset.UnsupportedCharsetException;

/**
 * General IO stream manipulation utilities.
 * <p>
 * This class provides static utility methods for input/output operations.
 * <ul>
 * <li>closeQuietly - these methods close a stream ignoring nulls and exceptions
 * <li>toXxx/read - these methods read data from a stream
 * <li>write - these methods write data to a stream
 * <li>copy - these methods copy all the data from one stream to another
 * <li>contentEquals - these methods compare the content of two streams
 * </ul>
 * <p>
 * The byte-to-char methods and char-to-byte methods involve a conversion step.
 * Two methods are provided in each case, one that uses the platform default
 * encoding and the other which allows you to specify an encoding. You are
 * encouraged to always specify an encoding because relying on the platform
 * default can lead to unexpected results, for example when moving from
 * development to production.
 * <p>
 * All the methods in this class that read a stream are buffered internally.
 * This means that there is no cause to use a <code>BufferedInputStream</code>
 * or <code>BufferedReader</code>. The default buffer size of 4K has been shown
 * to be efficient in tests.
 * <p>
 * Wherever possible, the methods in this class do <em>not</em> flush or close
 * the stream. This is to avoid making non-portable assumptions about the
 * streams' origin and further use. Thus the caller is still responsible for
 * closing streams after use.
 * <p>
 * Origin of code: Excalibur.
 * 
 * @version $Id: IOUtils.java 1326636 2012-04-16 14:54:53Z ggregory $
 */
public class IOUtils
{
    // NOTE: This class is focussed on InputStream, OutputStream, Reader and
    // Writer. Each method should take at least one of these as a parameter,
    // or return one of them.

    private static final int   EOF                    = -1;
    /**
     * The Unix directory separator character.
     */
    public static final char   DIR_SEPARATOR_UNIX     = '/';
    /**
     * The Windows directory separator character.
     */
    public static final char   DIR_SEPARATOR_WINDOWS  = '\\';
    /**
     * The system directory separator character.
     */
    public static final char   DIR_SEPARATOR          = File.separatorChar;
    /**
     * The Unix line separator string.
     */
    public static final String LINE_SEPARATOR_UNIX    = "\n";
    /**
     * The Windows line separator string.
     */
    public static final String LINE_SEPARATOR_WINDOWS = "\r\n";

    /**
     * The default buffer size ({@value} ) to use for
     * {@link #copyLarge(InputStream, OutputStream)} and
     * {@link #copyLarge(Reader, Writer)}
     */
    private static final int   DEFAULT_BUFFER_SIZE    = 1024 * 4;

    /**
     * The default buffer size to use for the skip() methods.
     */
    private static final int   SKIP_BUFFER_SIZE       = 2048;

    // Allocated in the relevant skip method if necessary.
    /*
     * N.B. no need to synchronize these because: - we don't care if the buffer
     * is created multiple times (the data is ignored) - we always use the same
     * size buffer, so if it it is recreated it will still be OK (if the buffer
     * size were variable, we would need to synch. to ensure some other thread
     * did not create a smaller one)
     */
    private static char[]      SKIP_CHAR_BUFFER;
    private static byte[]      SKIP_BYTE_BUFFER;

    /**
     * Instances should NOT be constructed in standard programming.
     */
    public IOUtils()
    {
        super();
    }

    // -----------------------------------------------------------------------

    /**
     * Closes a URLConnection.
     * 
     * @param conn
     *            the connection to close.
     * @since 2.4
     */
    public static void close(URLConnection conn)
    {
        if (conn instanceof HttpURLConnection)
        {
            ((HttpURLConnection) conn).disconnect();
        }
    }

    /**
     * Unconditionally close an <code>Reader</code>.
     * <p>
     * Equivalent to {@link Reader#close()}, except any exceptions will be
     * ignored. This is typically used in finally blocks.
     * <p>
     * Example code:
     * 
     * <pre>
     * char[] data = new char[1024];
     * Reader in = null;
     * try
     * {
     *     in = new FileReader(&quot;foo.txt&quot;);
     *     in.read(data);
     *     in.close(); // close errors are handled
     * }
     * catch (Exception e)
     * {
     *     // error handling
     * }
     * finally
     * {
     *     IOUtils.closeQuietly(in);
     * }
     * </pre>
     * 
     * @param input
     *            the Reader to close, may be null or already closed
     */
    public static void closeQuietly(Reader input)
    {
        closeQuietly((Closeable) input);
    }

    /**
     * Unconditionally close a <code>Writer</code>.
     * <p>
     * Equivalent to {@link Writer#close()}, except any exceptions will be
     * ignored. This is typically used in finally blocks.
     * <p>
     * Example code:
     * 
     * <pre>
     * Writer out = null;
     * try
     * {
     *     out = new StringWriter();
     *     out.write(&quot;Hello World&quot;);
     *     out.close(); // close errors are handled
     * }
     * catch (Exception e)
     * {
     *     // error handling
     * }
     * finally
     * {
     *     IOUtils.closeQuietly(out);
     * }
     * </pre>
     * 
     * @param output
     *            the Writer to close, may be null or already closed
     */
    public static void closeQuietly(Writer output)
    {
        closeQuietly((Closeable) output);
    }

    /**
     * Unconditionally close an <code>InputStream</code>.
     * <p>
     * Equivalent to {@link InputStream#close()}, except any exceptions will be
     * ignored. This is typically used in finally blocks.
     * <p>
     * Example code:
     * 
     * <pre>
     * byte[] data = new byte[1024];
     * InputStream in = null;
     * try
     * {
     *     in = new FileInputStream(&quot;foo.txt&quot;);
     *     in.read(data);
     *     in.close(); // close errors are handled
     * }
     * catch (Exception e)
     * {
     *     // error handling
     * }
     * finally
     * {
     *     IOUtils.closeQuietly(in);
     * }
     * </pre>
     * 
     * @param input
     *            the InputStream to close, may be null or already closed
     */
    public static void closeQuietly(InputStream input)
    {
        closeQuietly((Closeable) input);
    }

    /**
     * Unconditionally close an <code>OutputStream</code>.
     * <p>
     * Equivalent to {@link OutputStream#close()}, except any exceptions will be
     * ignored. This is typically used in finally blocks.
     * <p>
     * Example code:
     * 
     * <pre>
     * byte[] data = &quot;Hello, World&quot;.getBytes();
     * 
     * OutputStream out = null;
     * try
     * {
     *     out = new FileOutputStream(&quot;foo.txt&quot;);
     *     out.write(data);
     *     out.close(); // close errors are handled
     * }
     * catch (IOException e)
     * {
     *     // error handling
     * }
     * finally
     * {
     *     IOUtils.closeQuietly(out);
     * }
     * </pre>
     * 
     * @param output
     *            the OutputStream to close, may be null or already closed
     */
    public static void closeQuietly(OutputStream output)
    {
        closeQuietly((Closeable) output);
    }

    /**
     * Unconditionally close a <code>Closeable</code>.
     * <p>
     * Equivalent to {@link Closeable#close()}, except any exceptions will be
     * ignored. This is typically used in finally blocks.
     * <p>
     * Example code:
     * 
     * <pre>
     * Closeable closeable = null;
     * try
     * {
     *     closeable = new FileReader(&quot;foo.txt&quot;);
     *     // process closeable
     *     closeable.close();
     * }
     * catch (Exception e)
     * {
     *     // error handling
     * }
     * finally
     * {
     *     IOUtils.closeQuietly(closeable);
     * }
     * </pre>
     * 
     * @param closeable
     *            the object to close, may be null or already closed
     * @since 2.0
     */
    public static void closeQuietly(Closeable closeable)
    {
        try
        {
            if (closeable != null)
            {
                closeable.close();
            }
        }
        catch (IOException ioe)
        {
            // ignore
        }
    }

    /**
     * Unconditionally close a <code>Socket</code>.
     * <p>
     * Equivalent to {@link Socket#close()}, except any exceptions will be
     * ignored. This is typically used in finally blocks.
     * <p>
     * Example code:
     * 
     * <pre>
     * Socket socket = null;
     * try
     * {
     *     socket = new Socket(&quot;http://www.foo.com/&quot;, 80);
     *     // process socket
     *     socket.close();
     * }
     * catch (Exception e)
     * {
     *     // error handling
     * }
     * finally
     * {
     *     IOUtils.closeQuietly(socket);
     * }
     * </pre>
     * 
     * @param sock
     *            the Socket to close, may be null or already closed
     * @since 2.0
     */
    public static void closeQuietly(Socket sock)
    {
        if (sock != null)
        {
            try
            {
                sock.close();
            }
            catch (IOException ioe)
            {
                // ignored
            }
        }
    }

    /**
     * Unconditionally close a <code>Selector</code>.
     * <p>
     * Equivalent to {@link Selector#close()}, except any exceptions will be
     * ignored. This is typically used in finally blocks.
     * <p>
     * Example code:
     * 
     * <pre>
     * Selector selector = null;
     * try
     * {
     *     selector = Selector.open();
     *     // process socket
     * 
     * }
     * catch (Exception e)
     * {
     *     // error handling
     * }
     * finally
     * {
     *     IOUtils.closeQuietly(selector);
     * }
     * </pre>
     * 
     * @param selector
     *            the Selector to close, may be null or already closed
     * @since 2.2
     */
    public static void closeQuietly(Selector selector)
    {
        if (selector != null)
        {
            try
            {
                selector.close();
            }
            catch (IOException ioe)
            {
                // ignored
            }
        }
    }

    /**
     * Unconditionally close a <code>ServerSocket</code>.
     * <p>
     * Equivalent to {@link ServerSocket#close()}, except any exceptions will be
     * ignored. This is typically used in finally blocks.
     * <p>
     * Example code:
     * 
     * <pre>
     * ServerSocket socket = null;
     * try
     * {
     *     socket = new ServerSocket();
     *     // process socket
     *     socket.close();
     * }
     * catch (Exception e)
     * {
     *     // error handling
     * }
     * finally
     * {
     *     IOUtils.closeQuietly(socket);
     * }
     * </pre>
     * 
     * @param sock
     *            the ServerSocket to close, may be null or already closed
     * @since 2.2
     */
    public static void closeQuietly(ServerSocket sock)
    {
        if (sock != null)
        {
            try
            {
                sock.close();
            }
            catch (IOException ioe)
            {
                // ignored
            }
        }
    }

    /**
     * Returns the given reader if it is a {@link BufferedReader}, otherwise
     * creates a toBufferedReader for the given reader.
     * 
     * @param reader
     *            the reader to wrap or return
     * @return the given reader or a new {@link BufferedReader} for the given
     *         reader
     * @since 2.2
     */
    public static BufferedReader toBufferedReader(Reader reader)
    {
        return reader instanceof BufferedReader ? (BufferedReader) reader : new BufferedReader(reader);
    }

    // read toByteArray
    // -----------------------------------------------------------------------
    /**
     * Get the contents of an <code>InputStream</code> as a <code>byte[]</code>.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * 
     * @param input
     *            the <code>InputStream</code> to read from
     * @return the requested byte array
     * @throws NullPointerException
     *             if the input is null
     * @throws IOException
     *             if an I/O error occurs
     */
    public static byte[] toByteArray(InputStream input) throws IOException
    {
        ByteArrayOutputStream output = new ByteArrayOutputStream();
        copy(input, output);
        return output.toByteArray();
    }

    /**
     * Get contents of an <code>InputStream</code> as a <code>byte[]</code>. Use
     * this method instead of <code>toByteArray(InputStream)</code> when
     * <code>InputStream</code> size is known. <b>NOTE:</b> the method checks
     * that the length can safely be cast to an int without truncation before
     * using {@link IOUtils#toByteArray(java.io.InputStream, int)} to read into
     * the byte array. (Arrays can have no more than Integer.MAX_VALUE entries
     * anyway)
     * 
     * @param input
     *            the <code>InputStream</code> to read from
     * @param size
     *            the size of <code>InputStream</code>
     * @return the requested byte array
     * @throws IOException
     *             if an I/O error occurs or <code>InputStream</code> size
     *             differ from parameter size
     * @throws IllegalArgumentException
     *             if size is less than zero or size is greater than
     *             Integer.MAX_VALUE
     * @see IOUtils#toByteArray(java.io.InputStream, int)
     * @since 2.1
     */
    public static byte[] toByteArray(InputStream input, long size) throws IOException
    {

        if (size > Integer.MAX_VALUE)
        {
            throw new IllegalArgumentException("Size cannot be greater than Integer max value: " + size);
        }

        return toByteArray(input, (int) size);
    }

    /**
     * Get the contents of an <code>InputStream</code> as a <code>byte[]</code>.
     * Use this method instead of <code>toByteArray(InputStream)</code> when
     * <code>InputStream</code> size is known
     * 
     * @param input
     *            the <code>InputStream</code> to read from
     * @param size
     *            the size of <code>InputStream</code>
     * @return the requested byte array
     * @throws IOException
     *             if an I/O error occurs or <code>InputStream</code> size
     *             differ from parameter size
     * @throws IllegalArgumentException
     *             if size is less than zero
     * @since 2.1
     */
    public static byte[] toByteArray(InputStream input, int size) throws IOException
    {

        if (size < 0)
        {
            throw new IllegalArgumentException("Size must be equal or greater than zero: " + size);
        }

        if (size == 0)
        {
            return new byte[0];
        }

        byte[] data = new byte[size];
        int offset = 0;
        int readed;

        while (offset < size && (readed = input.read(data, offset, size - offset)) != EOF)
        {
            offset += readed;
        }

        if (offset != size)
        {
            throw new IOException("Unexpected readed size. current: " + offset + ", excepted: " + size);
        }

        return data;
    }

    /**
     * Get the contents of a <code>Reader</code> as a <code>byte[]</code> using
     * the default character encoding of the platform.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     * 
     * @param input
     *            the <code>Reader</code> to read from
     * @return the requested byte array
     * @throws NullPointerException
     *             if the input is null
     * @throws IOException
     *             if an I/O error occurs
     */
    public static byte[] toByteArray(Reader input) throws IOException
    {
        return toByteArray(input, Charset.defaultCharset());
    }

    /**
     * Get the contents of a <code>Reader</code> as a <code>byte[]</code> using
     * the specified character encoding.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     * 
     * @param input
     *            the <code>Reader</code> to read from
     * @param encoding
     *            the encoding to use, null means platform default
     * @return the requested byte array
     * @throws NullPointerException
     *             if the input is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 2.3
     */
    public static byte[] toByteArray(Reader input, Charset encoding) throws IOException
    {
        ByteArrayOutputStream output = new ByteArrayOutputStream();
        copy(input, output, encoding);
        return output.toByteArray();
    }

    /**
     * Get the contents of a <code>Reader</code> as a <code>byte[]</code> using
     * the specified character encoding.
     * <p>
     * Character encoding names can be found at <a
     * href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     * 
     * @param input
     *            the <code>Reader</code> to read from
     * @param encoding
     *            the encoding to use, null means platform default
     * @return the requested byte array
     * @throws NullPointerException
     *             if the input is null
     * @throws IOException
     *             if an I/O error occurs
     * @throws UnsupportedCharsetException
     *             thrown instead of {@link UnsupportedEncodingException} in
     *             version 2.2 if the encoding is not supported.
     * @since 1.1
     */
    public static byte[] toByteArray(Reader input, String encoding) throws IOException
    {
        return toByteArray(input, Charsets.toCharset(encoding));
    }

    /**
     * Get the contents of a <code>String</code> as a <code>byte[]</code> using
     * the default character encoding of the platform.
     * <p>
     * This is the same as {@link String#getBytes()}.
     * 
     * @param input
     *            the <code>String</code> to convert
     * @return the requested byte array
     * @throws NullPointerException
     *             if the input is null
     * @throws IOException
     *             if an I/O error occurs (never occurs)
     * @deprecated Use {@link String#getBytes()}
     */
    @Deprecated
    public static byte[] toByteArray(String input) throws IOException
    {
        return input.getBytes();
    }

    /**
     * Get the contents of a <code>URI</code> as a <code>byte[]</code>.
     * 
     * @param uri
     *            the <code>URI</code> to read
     * @return the requested byte array
     * @throws NullPointerException
     *             if the uri is null
     * @throws IOException
     *             if an I/O exception occurs
     * @since 2.4
     */
    public static byte[] toByteArray(URI uri) throws IOException
    {
        return IOUtils.toByteArray(uri.toURL());
    }

    /**
     * Get the contents of a <code>URL</code> as a <code>byte[]</code>.
     * 
     * @param url
     *            the <code>URL</code> to read
     * @return the requested byte array
     * @throws NullPointerException
     *             if the input is null
     * @throws IOException
     *             if an I/O exception occurs
     * @since 2.4
     */
    public static byte[] toByteArray(URL url) throws IOException
    {
        URLConnection conn = url.openConnection();
        try
        {
            return IOUtils.toByteArray(conn);
        }
        finally
        {
            close(conn);
        }
    }

    /**
     * Get the contents of a <code>URLConnection</code> as a <code>byte[]</code>
     * .
     * 
     * @param urlConn
     *            the <code>URLConnection</code> to read
     * @return the requested byte array
     * @throws NullPointerException
     *             if the urlConn is null
     * @throws IOException
     *             if an I/O exception occurs
     * @since 2.4
     */
    public static byte[] toByteArray(URLConnection urlConn) throws IOException
    {
        InputStream inputStream = urlConn.getInputStream();
        try
        {
            return IOUtils.toByteArray(inputStream);
        }
        finally
        {
            inputStream.close();
        }
    }

    // read char[]
    // -----------------------------------------------------------------------
    /**
     * Get the contents of an <code>InputStream</code> as a character array
     * using the default character encoding of the platform.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * 
     * @param is
     *            the <code>InputStream</code> to read from
     * @return the requested character array
     * @throws NullPointerException
     *             if the input is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 1.1
     */
    public static char[] toCharArray(InputStream is) throws IOException
    {
        return toCharArray(is, Charset.defaultCharset());
    }

    /**
     * Get the contents of an <code>InputStream</code> as a character array
     * using the specified character encoding.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * 
     * @param is
     *            the <code>InputStream</code> to read from
     * @param encoding
     *            the encoding to use, null means platform default
     * @return the requested character array
     * @throws NullPointerException
     *             if the input is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 2.3
     */
    public static char[] toCharArray(InputStream is, Charset encoding) throws IOException
    {
        CharArrayWriter output = new CharArrayWriter();
        copy(is, output, encoding);
        return output.toCharArray();
    }

    /**
     * Get the contents of an <code>InputStream</code> as a character array
     * using the specified character encoding.
     * <p>
     * Character encoding names can be found at <a
     * href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * 
     * @param is
     *            the <code>InputStream</code> to read from
     * @param encoding
     *            the encoding to use, null means platform default
     * @return the requested character array
     * @throws NullPointerException
     *             if the input is null
     * @throws IOException
     *             if an I/O error occurs
     * @throws UnsupportedCharsetException
     *             thrown instead of {@link UnsupportedEncodingException} in
     *             version 2.2 if the encoding is not supported.
     * @since 1.1
     */
    public static char[] toCharArray(InputStream is, String encoding) throws IOException
    {
        return toCharArray(is, Charsets.toCharset(encoding));
    }

    /**
     * Get the contents of a <code>Reader</code> as a character array.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     * 
     * @param input
     *            the <code>Reader</code> to read from
     * @return the requested character array
     * @throws NullPointerException
     *             if the input is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 1.1
     */
    public static char[] toCharArray(Reader input) throws IOException
    {
        CharArrayWriter sw = new CharArrayWriter();
        copy(input, sw);
        return sw.toCharArray();
    }

    // -----------------------------------------------------------------------
    /**
     * Convert the specified CharSequence to an input stream, encoded as bytes
     * using the default character encoding of the platform.
     * 
     * @param input
     *            the CharSequence to convert
     * @return an input stream
     * @since 2.0
     */
    public static InputStream toInputStream(CharSequence input)
    {
        return toInputStream(input, Charset.defaultCharset());
    }

    /**
     * Convert the specified CharSequence to an input stream, encoded as bytes
     * using the specified character encoding.
     * 
     * @param input
     *            the CharSequence to convert
     * @param encoding
     *            the encoding to use, null means platform default
     * @return an input stream
     * @since 2.3
     */
    public static InputStream toInputStream(CharSequence input, Charset encoding)
    {
        return toInputStream(input.toString(), encoding);
    }

    /**
     * Convert the specified CharSequence to an input stream, encoded as bytes
     * using the specified character encoding.
     * <p>
     * Character encoding names can be found at <a
     * href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * 
     * @param input
     *            the CharSequence to convert
     * @param encoding
     *            the encoding to use, null means platform default
     * @return an input stream
     * @throws IOException
     *             if the encoding is invalid
     * @throws UnsupportedCharsetException
     *             thrown instead of {@link UnsupportedEncodingException} in
     *             version 2.2 if the encoding is not supported.
     * @since 2.0
     */
    public static InputStream toInputStream(CharSequence input, String encoding) throws IOException
    {
        return toInputStream(input, Charsets.toCharset(encoding));
    }

    // -----------------------------------------------------------------------
    /**
     * Convert the specified string to an input stream, encoded as bytes using
     * the default character encoding of the platform.
     * 
     * @param input
     *            the string to convert
     * @return an input stream
     * @since 1.1
     */
    public static InputStream toInputStream(String input)
    {
        return toInputStream(input, Charset.defaultCharset());
    }

    // write byte[]
    // -----------------------------------------------------------------------
    /**
     * Writes bytes from a <code>byte[]</code> to an <code>OutputStream</code>.
     * 
     * @param data
     *            the byte array to write, do not modify during output, null
     *            ignored
     * @param output
     *            the <code>OutputStream</code> to write to
     * @throws NullPointerException
     *             if output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 1.1
     */
    public static void write(byte[] data, OutputStream output) throws IOException
    {
        if (data != null)
        {
            output.write(data);
        }
    }

    // write char[]
    // -----------------------------------------------------------------------
    /**
     * Writes chars from a <code>char[]</code> to a <code>Writer</code> using
     * the default character encoding of the platform.
     * 
     * @param data
     *            the char array to write, do not modify during output, null
     *            ignored
     * @param output
     *            the <code>Writer</code> to write to
     * @throws NullPointerException
     *             if output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 1.1
     */
    public static void write(char[] data, Writer output) throws IOException
    {
        if (data != null)
        {
            output.write(data);
        }
    }

    // write CharSequence
    // -----------------------------------------------------------------------
    /**
     * Writes chars from a <code>CharSequence</code> to a <code>Writer</code>.
     * 
     * @param data
     *            the <code>CharSequence</code> to write, null ignored
     * @param output
     *            the <code>Writer</code> to write to
     * @throws NullPointerException
     *             if output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 2.0
     */
    public static void write(CharSequence data, Writer output) throws IOException
    {
        if (data != null)
        {
            write(data.toString(), output);
        }
    }

    /**
     * Writes chars from a <code>CharSequence</code> to bytes on an
     * <code>OutputStream</code> using the default character encoding of the
     * platform.
     * <p>
     * This method uses {@link String#getBytes()}.
     * 
     * @param data
     *            the <code>CharSequence</code> to write, null ignored
     * @param output
     *            the <code>OutputStream</code> to write to
     * @throws NullPointerException
     *             if output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 2.0
     */
    public static void write(CharSequence data, OutputStream output) throws IOException
    {
        write(data, output, Charset.defaultCharset());
    }

    /**
     * Writes chars from a <code>CharSequence</code> to bytes on an
     * <code>OutputStream</code> using the specified character encoding.
     * <p>
     * This method uses {@link String#getBytes(String)}.
     * 
     * @param data
     *            the <code>CharSequence</code> to write, null ignored
     * @param output
     *            the <code>OutputStream</code> to write to
     * @param encoding
     *            the encoding to use, null means platform default
     * @throws NullPointerException
     *             if output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 2.3
     */
    public static void write(CharSequence data, OutputStream output, Charset encoding) throws IOException
    {
        if (data != null)
        {
            write(data.toString(), output, encoding);
        }
    }

    /**
     * Writes chars from a <code>CharSequence</code> to bytes on an
     * <code>OutputStream</code> using the specified character encoding.
     * <p>
     * Character encoding names can be found at <a
     * href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method uses {@link String#getBytes(String)}.
     * 
     * @param data
     *            the <code>CharSequence</code> to write, null ignored
     * @param output
     *            the <code>OutputStream</code> to write to
     * @param encoding
     *            the encoding to use, null means platform default
     * @throws NullPointerException
     *             if output is null
     * @throws IOException
     *             if an I/O error occurs
     * @throws UnsupportedCharsetException
     *             thrown instead of {@link UnsupportedEncodingException} in
     *             version 2.2 if the encoding is not supported.
     * @since 2.0
     */
    public static void write(CharSequence data, OutputStream output, String encoding) throws IOException
    {
        write(data, output, Charsets.toCharset(encoding));
    }

    // write String
    // -----------------------------------------------------------------------
    /**
     * Writes chars from a <code>String</code> to a <code>Writer</code>.
     * 
     * @param data
     *            the <code>String</code> to write, null ignored
     * @param output
     *            the <code>Writer</code> to write to
     * @throws NullPointerException
     *             if output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 1.1
     */
    public static void write(String data, Writer output) throws IOException
    {
        if (data != null)
        {
            output.write(data);
        }
    }

    /**
     * Writes chars from a <code>String</code> to bytes on an
     * <code>OutputStream</code> using the default character encoding of the
     * platform.
     * <p>
     * This method uses {@link String#getBytes()}.
     * 
     * @param data
     *            the <code>String</code> to write, null ignored
     * @param output
     *            the <code>OutputStream</code> to write to
     * @throws NullPointerException
     *             if output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 1.1
     */
    public static void write(String data, OutputStream output) throws IOException
    {
        write(data, output, Charset.defaultCharset());
    }

    /**
     * Writes chars from a <code>String</code> to bytes on an
     * <code>OutputStream</code> using the specified character encoding.
     * <p>
     * Character encoding names can be found at <a
     * href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method uses {@link String#getBytes(String)}.
     * 
     * @param data
     *            the <code>String</code> to write, null ignored
     * @param output
     *            the <code>OutputStream</code> to write to
     * @param encoding
     *            the encoding to use, null means platform default
     * @throws NullPointerException
     *             if output is null
     * @throws IOException
     *             if an I/O error occurs
     * @throws UnsupportedCharsetException
     *             thrown instead of {@link UnsupportedEncodingException} in
     *             version 2.2 if the encoding is not supported.
     * @since 1.1
     */
    public static void write(String data, OutputStream output, String encoding) throws IOException
    {
        write(data, output, Charsets.toCharset(encoding));
    }

    // write StringBuffer
    // -----------------------------------------------------------------------
    /**
     * Writes chars from a <code>StringBuffer</code> to a <code>Writer</code>.
     * 
     * @param data
     *            the <code>StringBuffer</code> to write, null ignored
     * @param output
     *            the <code>Writer</code> to write to
     * @throws NullPointerException
     *             if output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 1.1
     * @deprecated replaced by write(CharSequence, Writer)
     */
    @Deprecated
    public static void write(StringBuffer data, Writer output) throws IOException
    {
        if (data != null)
        {
            output.write(data.toString());
        }
    }

    // copy from InputStream
    // -----------------------------------------------------------------------
    /**
     * Copy bytes from an <code>InputStream</code> to an
     * <code>OutputStream</code>.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * <p>
     * Large streams (over 2GB) will return a bytes copied value of
     * <code>-1</code> after the copy has completed since the correct number of
     * bytes cannot be returned as an int. For large streams use the
     * <code>copyLarge(InputStream, OutputStream)</code> method.
     * 
     * @param input
     *            the <code>InputStream</code> to read from
     * @param output
     *            the <code>OutputStream</code> to write to
     * @return the number of bytes copied, or -1 if &gt; Integer.MAX_VALUE
     * @throws NullPointerException
     *             if the input or output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 1.1
     */
    public static int copy(InputStream input, OutputStream output) throws IOException
    {
        long count = copyLarge(input, output);
        if (count > Integer.MAX_VALUE)
        {
            return -1;
        }
        return (int) count;
    }

    /**
     * Copy bytes from a large (over 2GB) <code>InputStream</code> to an
     * <code>OutputStream</code>.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * <p>
     * The buffer size is given by {@link #DEFAULT_BUFFER_SIZE}.
     * 
     * @param input
     *            the <code>InputStream</code> to read from
     * @param output
     *            the <code>OutputStream</code> to write to
     * @return the number of bytes copied
     * @throws NullPointerException
     *             if the input or output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 1.3
     */
    public static long copyLarge(InputStream input, OutputStream output) throws IOException
    {
        return copyLarge(input, output, new byte[DEFAULT_BUFFER_SIZE]);
    }

    /**
     * Copy bytes from a large (over 2GB) <code>InputStream</code> to an
     * <code>OutputStream</code>.
     * <p>
     * This method uses the provided buffer, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * <p>
     * 
     * @param input
     *            the <code>InputStream</code> to read from
     * @param output
     *            the <code>OutputStream</code> to write to
     * @param buffer
     *            the buffer to use for the copy
     * @return the number of bytes copied
     * @throws NullPointerException
     *             if the input or output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 2.2
     */
    public static long copyLarge(InputStream input, OutputStream output, byte[] buffer) throws IOException
    {
        long count = 0;
        int n = 0;
        while (EOF != (n = input.read(buffer)))
        {
            output.write(buffer, 0, n);
            count += n;
        }
        return count;
    }

    /**
     * Copy some or all bytes from a large (over 2GB) <code>InputStream</code>
     * to an <code>OutputStream</code>, optionally skipping input bytes.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * <p>
     * The buffer size is given by {@link #DEFAULT_BUFFER_SIZE}.
     * 
     * @param input
     *            the <code>InputStream</code> to read from
     * @param output
     *            the <code>OutputStream</code> to write to
     * @param inputOffset
     *            : number of bytes to skip from input before copying -ve values
     *            are ignored
     * @param length
     *            : number of bytes to copy. -ve means all
     * @return the number of bytes copied
     * @throws NullPointerException
     *             if the input or output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 2.2
     */
    public static long copyLarge(InputStream input, OutputStream output, long inputOffset, long length) throws IOException
    {
        return copyLarge(input, output, inputOffset, length, new byte[DEFAULT_BUFFER_SIZE]);
    }

    /**
     * Copy some or all bytes from a large (over 2GB) <code>InputStream</code>
     * to an <code>OutputStream</code>, optionally skipping input bytes.
     * <p>
     * This method uses the provided buffer, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * <p>
     * 
     * @param input
     *            the <code>InputStream</code> to read from
     * @param output
     *            the <code>OutputStream</code> to write to
     * @param inputOffset
     *            : number of bytes to skip from input before copying -ve values
     *            are ignored
     * @param length
     *            : number of bytes to copy. -ve means all
     * @param buffer
     *            the buffer to use for the copy
     * 
     * @return the number of bytes copied
     * @throws NullPointerException
     *             if the input or output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 2.2
     */
    public static long copyLarge(InputStream input, OutputStream output, final long inputOffset, final long length, byte[] buffer) throws IOException
    {
        if (inputOffset > 0)
        {
            skipFully(input, inputOffset);
        }
        if (length == 0)
        {
            return 0;
        }
        final int bufferLength = buffer.length;
        int bytesToRead = bufferLength;
        if (length > 0 && length < bufferLength)
        {
            bytesToRead = (int) length;
        }
        int read;
        long totalRead = 0;
        while (bytesToRead > 0 && EOF != (read = input.read(buffer, 0, bytesToRead)))
        {
            output.write(buffer, 0, read);
            totalRead += read;
            if (length > 0)
            { // only adjust length if not reading to the end
              // Note the cast must work because buffer.length is an integer
                bytesToRead = (int) Math.min(length - totalRead, bufferLength);
            }
        }
        return totalRead;
    }

    /**
     * Copy bytes from an <code>InputStream</code> to chars on a
     * <code>Writer</code> using the default character encoding of the platform.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * <p>
     * This method uses {@link InputStreamReader}.
     * 
     * @param input
     *            the <code>InputStream</code> to read from
     * @param output
     *            the <code>Writer</code> to write to
     * @throws NullPointerException
     *             if the input or output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 1.1
     */
    public static void copy(InputStream input, Writer output) throws IOException
    {
        copy(input, output, Charset.defaultCharset());
    }

    /**
     * Copy bytes from an <code>InputStream</code> to chars on a
     * <code>Writer</code> using the specified character encoding.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * <p>
     * This method uses {@link InputStreamReader}.
     * 
     * @param input
     *            the <code>InputStream</code> to read from
     * @param output
     *            the <code>Writer</code> to write to
     * @param encoding
     *            the encoding to use, null means platform default
     * @throws NullPointerException
     *             if the input or output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 2.3
     */
    public static void copy(InputStream input, Writer output, Charset encoding) throws IOException
    {
        InputStreamReader in = new InputStreamReader(input, Charsets.toCharset(encoding));
        copy(in, output);
    }

    /**
     * Copy bytes from an <code>InputStream</code> to chars on a
     * <code>Writer</code> using the specified character encoding.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedInputStream</code>.
     * <p>
     * Character encoding names can be found at <a
     * href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * This method uses {@link InputStreamReader}.
     * 
     * @param input
     *            the <code>InputStream</code> to read from
     * @param output
     *            the <code>Writer</code> to write to
     * @param encoding
     *            the encoding to use, null means platform default
     * @throws NullPointerException
     *             if the input or output is null
     * @throws IOException
     *             if an I/O error occurs
     * @throws UnsupportedCharsetException
     *             thrown instead of {@link UnsupportedEncodingException} in
     *             version 2.2 if the encoding is not supported.
     * @since 1.1
     */
    public static void copy(InputStream input, Writer output, String encoding) throws IOException
    {
        copy(input, output, Charsets.toCharset(encoding));
    }

    // copy from Reader
    // -----------------------------------------------------------------------
    /**
     * Copy chars from a <code>Reader</code> to a <code>Writer</code>.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     * <p>
     * Large streams (over 2GB) will return a chars copied value of
     * <code>-1</code> after the copy has completed since the correct number of
     * chars cannot be returned as an int. For large streams use the
     * <code>copyLarge(Reader, Writer)</code> method.
     * 
     * @param input
     *            the <code>Reader</code> to read from
     * @param output
     *            the <code>Writer</code> to write to
     * @return the number of characters copied, or -1 if &gt; Integer.MAX_VALUE
     * @throws NullPointerException
     *             if the input or output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 1.1
     */
    public static int copy(Reader input, Writer output) throws IOException
    {
        long count = copyLarge(input, output);
        if (count > Integer.MAX_VALUE)
        {
            return -1;
        }
        return (int) count;
    }

    /**
     * Copy chars from a large (over 2GB) <code>Reader</code> to a
     * <code>Writer</code>.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     * <p>
     * The buffer size is given by {@link #DEFAULT_BUFFER_SIZE}.
     * 
     * @param input
     *            the <code>Reader</code> to read from
     * @param output
     *            the <code>Writer</code> to write to
     * @return the number of characters copied
     * @throws NullPointerException
     *             if the input or output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 1.3
     */
    public static long copyLarge(Reader input, Writer output) throws IOException
    {
        return copyLarge(input, output, new char[DEFAULT_BUFFER_SIZE]);
    }

    /**
     * Copy chars from a large (over 2GB) <code>Reader</code> to a
     * <code>Writer</code>.
     * <p>
     * This method uses the provided buffer, so there is no need to use a
     * <code>BufferedReader</code>.
     * <p>
     * 
     * @param input
     *            the <code>Reader</code> to read from
     * @param output
     *            the <code>Writer</code> to write to
     * @param buffer
     *            the buffer to be used for the copy
     * @return the number of characters copied
     * @throws NullPointerException
     *             if the input or output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 2.2
     */
    public static long copyLarge(Reader input, Writer output, char[] buffer) throws IOException
    {
        long count = 0;
        int n = 0;
        while (EOF != (n = input.read(buffer)))
        {
            output.write(buffer, 0, n);
            count += n;
        }
        return count;
    }

    /**
     * Copy some or all chars from a large (over 2GB) <code>InputStream</code>
     * to an <code>OutputStream</code>, optionally skipping input chars.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     * <p>
     * The buffer size is given by {@link #DEFAULT_BUFFER_SIZE}.
     * 
     * @param input
     *            the <code>Reader</code> to read from
     * @param output
     *            the <code>Writer</code> to write to
     * @param inputOffset
     *            : number of chars to skip from input before copying -ve values
     *            are ignored
     * @param length
     *            : number of chars to copy. -ve means all
     * @return the number of chars copied
     * @throws NullPointerException
     *             if the input or output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 2.2
     */
    public static long copyLarge(Reader input, Writer output, final long inputOffset, final long length) throws IOException
    {
        return copyLarge(input, output, inputOffset, length, new char[DEFAULT_BUFFER_SIZE]);
    }

    /**
     * Copy some or all chars from a large (over 2GB) <code>InputStream</code>
     * to an <code>OutputStream</code>, optionally skipping input chars.
     * <p>
     * This method uses the provided buffer, so there is no need to use a
     * <code>BufferedReader</code>.
     * <p>
     * 
     * @param input
     *            the <code>Reader</code> to read from
     * @param output
     *            the <code>Writer</code> to write to
     * @param inputOffset
     *            : number of chars to skip from input before copying -ve values
     *            are ignored
     * @param length
     *            : number of chars to copy. -ve means all
     * @param buffer
     *            the buffer to be used for the copy
     * @return the number of chars copied
     * @throws NullPointerException
     *             if the input or output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 2.2
     */
    public static long copyLarge(Reader input, Writer output, final long inputOffset, final long length, char[] buffer) throws IOException
    {
        if (inputOffset > 0)
        {
            skipFully(input, inputOffset);
        }
        if (length == 0)
        {
            return 0;
        }
        int bytesToRead = buffer.length;
        if (length > 0 && length < buffer.length)
        {
            bytesToRead = (int) length;
        }
        int read;
        long totalRead = 0;
        while (bytesToRead > 0 && EOF != (read = input.read(buffer, 0, bytesToRead)))
        {
            output.write(buffer, 0, read);
            totalRead += read;
            if (length > 0)
            { // only adjust length if not reading to the end
              // Note the cast must work because buffer.length is an integer
                bytesToRead = (int) Math.min(length - totalRead, buffer.length);
            }
        }
        return totalRead;
    }

    /**
     * Copy chars from a <code>Reader</code> to bytes on an
     * <code>OutputStream</code> using the default character encoding of the
     * platform, and calling flush.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     * <p>
     * Due to the implementation of OutputStreamWriter, this method performs a
     * flush.
     * <p>
     * This method uses {@link OutputStreamWriter}.
     * 
     * @param input
     *            the <code>Reader</code> to read from
     * @param output
     *            the <code>OutputStream</code> to write to
     * @throws NullPointerException
     *             if the input or output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 1.1
     */
    public static void copy(Reader input, OutputStream output) throws IOException
    {
        copy(input, output, Charset.defaultCharset());
    }

    /**
     * Copy chars from a <code>Reader</code> to bytes on an
     * <code>OutputStream</code> using the specified character encoding, and
     * calling flush.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     * </p>
     * <p>
     * Due to the implementation of OutputStreamWriter, this method performs a
     * flush.
     * </p>
     * <p>
     * This method uses {@link OutputStreamWriter}.
     * </p>
     * 
     * @param input
     *            the <code>Reader</code> to read from
     * @param output
     *            the <code>OutputStream</code> to write to
     * @param encoding
     *            the encoding to use, null means platform default
     * @throws NullPointerException
     *             if the input or output is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 2.3
     */
    public static void copy(Reader input, OutputStream output, Charset encoding) throws IOException
    {
        OutputStreamWriter out = new OutputStreamWriter(output, Charsets.toCharset(encoding));
        copy(input, out);
        // XXX Unless anyone is planning on rewriting OutputStreamWriter,
        // we have to flush here.
        out.flush();
    }

    /**
     * Copy chars from a <code>Reader</code> to bytes on an
     * <code>OutputStream</code> using the specified character encoding, and
     * calling flush.
     * <p>
     * This method buffers the input internally, so there is no need to use a
     * <code>BufferedReader</code>.
     * <p>
     * Character encoding names can be found at <a
     * href="http://www.iana.org/assignments/character-sets">IANA</a>.
     * <p>
     * Due to the implementation of OutputStreamWriter, this method performs a
     * flush.
     * <p>
     * This method uses {@link OutputStreamWriter}.
     * 
     * @param input
     *            the <code>Reader</code> to read from
     * @param output
     *            the <code>OutputStream</code> to write to
     * @param encoding
     *            the encoding to use, null means platform default
     * @throws NullPointerException
     *             if the input or output is null
     * @throws IOException
     *             if an I/O error occurs
     * @throws UnsupportedCharsetException
     *             thrown instead of {@link UnsupportedEncodingException} in
     *             version 2.2 if the encoding is not supported.
     * @since 1.1
     */
    public static void copy(Reader input, OutputStream output, String encoding) throws IOException
    {
        copy(input, output, Charsets.toCharset(encoding));
    }

    // content equals
    // -----------------------------------------------------------------------
    /**
     * Compare the contents of two Streams to determine if they are equal or
     * not.
     * <p>
     * This method buffers the input internally using
     * <code>BufferedInputStream</code> if they are not already buffered.
     * 
     * @param input1
     *            the first stream
     * @param input2
     *            the second stream
     * @return true if the content of the streams are equal or they both don't
     *         exist, false otherwise
     * @throws NullPointerException
     *             if either input is null
     * @throws IOException
     *             if an I/O error occurs
     */
    public static boolean contentEquals(InputStream input1, InputStream input2) throws IOException
    {
        if (!(input1 instanceof BufferedInputStream))
        {
            input1 = new BufferedInputStream(input1);
        }
        if (!(input2 instanceof BufferedInputStream))
        {
            input2 = new BufferedInputStream(input2);
        }

        int ch = input1.read();
        while (EOF != ch)
        {
            int ch2 = input2.read();
            if (ch != ch2)
            {
                return false;
            }
            ch = input1.read();
        }

        int ch2 = input2.read();
        return ch2 == EOF;
    }

    /**
     * Compare the contents of two Readers to determine if they are equal or
     * not.
     * <p>
     * This method buffers the input internally using
     * <code>BufferedReader</code> if they are not already buffered.
     * 
     * @param input1
     *            the first reader
     * @param input2
     *            the second reader
     * @return true if the content of the readers are equal or they both don't
     *         exist, false otherwise
     * @throws NullPointerException
     *             if either input is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 1.1
     */
    public static boolean contentEquals(Reader input1, Reader input2) throws IOException
    {

        input1 = toBufferedReader(input1);
        input2 = toBufferedReader(input2);

        int ch = input1.read();
        while (EOF != ch)
        {
            int ch2 = input2.read();
            if (ch != ch2)
            {
                return false;
            }
            ch = input1.read();
        }

        int ch2 = input2.read();
        return ch2 == EOF;
    }

    /**
     * Compare the contents of two Readers to determine if they are equal or
     * not, ignoring EOL characters.
     * <p>
     * This method buffers the input internally using
     * <code>BufferedReader</code> if they are not already buffered.
     * 
     * @param input1
     *            the first reader
     * @param input2
     *            the second reader
     * @return true if the content of the readers are equal (ignoring EOL
     *         differences), false otherwise
     * @throws NullPointerException
     *             if either input is null
     * @throws IOException
     *             if an I/O error occurs
     * @since 2.2
     */
    public static boolean contentEqualsIgnoreEOL(Reader input1, Reader input2) throws IOException
    {
        BufferedReader br1 = toBufferedReader(input1);
        BufferedReader br2 = toBufferedReader(input2);

        String line1 = br1.readLine();
        String line2 = br2.readLine();
        while (line1 != null && line2 != null && line1.equals(line2))
        {
            line1 = br1.readLine();
            line2 = br2.readLine();
        }
        return line1 == null ? line2 == null ? true : false : line1.equals(line2);
    }

    /**
     * Skip bytes from an input byte stream. This implementation guarantees that
     * it will read as many bytes as possible before giving up; this may not
     * always be the case for subclasses of {@link Reader}.
     * 
     * @param input
     *            byte stream to skip
     * @param toSkip
     *            number of bytes to skip.
     * @return number of bytes actually skipped.
     * 
     * @see InputStream#skip(long)
     * 
     * @throws IOException
     *             if there is a problem reading the file
     * @throws IllegalArgumentException
     *             if toSkip is negative
     * @since 2.0
     */
    public static long skip(InputStream input, long toSkip) throws IOException
    {
        if (toSkip < 0)
        {
            throw new IllegalArgumentException("Skip count must be non-negative, actual: " + toSkip);
        }
        /*
         * N.B. no need to synchronize this because: - we don't care if the
         * buffer is created multiple times (the data is ignored) - we always
         * use the same size buffer, so if it it is recreated it will still be
         * OK (if the buffer size were variable, we would need to synch. to
         * ensure some other thread did not create a smaller one)
         */
        if (SKIP_BYTE_BUFFER == null)
        {
            SKIP_BYTE_BUFFER = new byte[SKIP_BUFFER_SIZE];
        }
        long remain = toSkip;
        while (remain > 0)
        {
            long n = input.read(SKIP_BYTE_BUFFER, 0, (int) Math.min(remain, SKIP_BUFFER_SIZE));
            if (n < 0)
            { // EOF
                break;
            }
            remain -= n;
        }
        return toSkip - remain;
    }

    /**
     * Skip characters from an input character stream. This implementation
     * guarantees that it will read as many characters as possible before giving
     * up; this may not always be the case for subclasses of {@link Reader}.
     * 
     * @param input
     *            character stream to skip
     * @param toSkip
     *            number of characters to skip.
     * @return number of characters actually skipped.
     * 
     * @see Reader#skip(long)
     * 
     * @throws IOException
     *             if there is a problem reading the file
     * @throws IllegalArgumentException
     *             if toSkip is negative
     * @since 2.0
     */
    public static long skip(Reader input, long toSkip) throws IOException
    {
        if (toSkip < 0)
        {
            throw new IllegalArgumentException("Skip count must be non-negative, actual: " + toSkip);
        }
        /*
         * N.B. no need to synchronize this because: - we don't care if the
         * buffer is created multiple times (the data is ignored) - we always
         * use the same size buffer, so if it it is recreated it will still be
         * OK (if the buffer size were variable, we would need to synch. to
         * ensure some other thread did not create a smaller one)
         */
        if (SKIP_CHAR_BUFFER == null)
        {
            SKIP_CHAR_BUFFER = new char[SKIP_BUFFER_SIZE];
        }
        long remain = toSkip;
        while (remain > 0)
        {
            long n = input.read(SKIP_CHAR_BUFFER, 0, (int) Math.min(remain, SKIP_BUFFER_SIZE));
            if (n < 0)
            { // EOF
                break;
            }
            remain -= n;
        }
        return toSkip - remain;
    }

    /**
     * Skip the requested number of bytes or fail if there are not enough left.
     * <p>
     * This allows for the possibility that {@link InputStream#skip(long)} may
     * not skip as many bytes as requested (most likely because of reaching
     * EOF).
     * 
     * @param input
     *            stream to skip
     * @param toSkip
     *            the number of bytes to skip
     * @see InputStream#skip(long)
     * 
     * @throws IOException
     *             if there is a problem reading the file
     * @throws IllegalArgumentException
     *             if toSkip is negative
     * @throws EOFException
     *             if the number of bytes skipped was incorrect
     * @since 2.0
     */
    public static void skipFully(InputStream input, long toSkip) throws IOException
    {
        if (toSkip < 0)
        {
            throw new IllegalArgumentException("Bytes to skip must not be negative: " + toSkip);
        }
        long skipped = skip(input, toSkip);
        if (skipped != toSkip)
        {
            throw new EOFException("Bytes to skip: " + toSkip + " actual: " + skipped);
        }
    }

    /**
     * Skip the requested number of characters or fail if there are not enough
     * left.
     * <p>
     * This allows for the possibility that {@link Reader#skip(long)} may not
     * skip as many characters as requested (most likely because of reaching
     * EOF).
     * 
     * @param input
     *            stream to skip
     * @param toSkip
     *            the number of characters to skip
     * @see Reader#skip(long)
     * 
     * @throws IOException
     *             if there is a problem reading the file
     * @throws IllegalArgumentException
     *             if toSkip is negative
     * @throws EOFException
     *             if the number of characters skipped was incorrect
     * @since 2.0
     */
    public static void skipFully(Reader input, long toSkip) throws IOException
    {
        long skipped = skip(input, toSkip);
        if (skipped != toSkip)
        {
            throw new EOFException("Chars to skip: " + toSkip + " actual: " + skipped);
        }
    }

    /**
     * Read characters from an input character stream. This implementation
     * guarantees that it will read as many characters as possible before giving
     * up; this may not always be the case for subclasses of {@link Reader}.
     * 
     * @param input
     *            where to read input from
     * @param buffer
     *            destination
     * @param offset
     *            inital offset into buffer
     * @param length
     *            length to read, must be >= 0
     * @return actual length read; may be less than requested if EOF was reached
     * @throws IOException
     *             if a read error occurs
     * @since 2.2
     */
    public static int read(Reader input, char[] buffer, int offset, int length) throws IOException
    {
        if (length < 0)
        {
            throw new IllegalArgumentException("Length must not be negative: " + length);
        }
        int remaining = length;
        while (remaining > 0)
        {
            int location = length - remaining;
            int count = input.read(buffer, offset + location, remaining);
            if (EOF == count)
            { // EOF
                break;
            }
            remaining -= count;
        }
        return length - remaining;
    }

    /**
     * Read characters from an input character stream. This implementation
     * guarantees that it will read as many characters as possible before giving
     * up; this may not always be the case for subclasses of {@link Reader}.
     * 
     * @param input
     *            where to read input from
     * @param buffer
     *            destination
     * @return actual length read; may be less than requested if EOF was reached
     * @throws IOException
     *             if a read error occurs
     * @since 2.2
     */
    public static int read(Reader input, char[] buffer) throws IOException
    {
        return read(input, buffer, 0, buffer.length);
    }

    /**
     * Read bytes from an input stream. This implementation guarantees that it
     * will read as many bytes as possible before giving up; this may not always
     * be the case for subclasses of {@link InputStream}.
     * 
     * @param input
     *            where to read input from
     * @param buffer
     *            destination
     * @param offset
     *            inital offset into buffer
     * @param length
     *            length to read, must be >= 0
     * @return actual length read; may be less than requested if EOF was reached
     * @throws IOException
     *             if a read error occurs
     * @since 2.2
     */
    public static int read(InputStream input, byte[] buffer, int offset, int length) throws IOException
    {
        if (length < 0)
        {
            throw new IllegalArgumentException("Length must not be negative: " + length);
        }
        int remaining = length;
        while (remaining > 0)
        {
            int location = length - remaining;
            int count = input.read(buffer, offset + location, remaining);
            if (EOF == count)
            { // EOF
                break;
            }
            remaining -= count;
        }
        return length - remaining;
    }

    /**
     * Read bytes from an input stream. This implementation guarantees that it
     * will read as many bytes as possible before giving up; this may not always
     * be the case for subclasses of {@link InputStream}.
     * 
     * @param input
     *            where to read input from
     * @param buffer
     *            destination
     * @return actual length read; may be less than requested if EOF was reached
     * @throws IOException
     *             if a read error occurs
     * @since 2.2
     */
    public static int read(InputStream input, byte[] buffer) throws IOException
    {
        return read(input, buffer, 0, buffer.length);
    }

    /**
     * Read the requested number of characters or fail if there are not enough
     * left.
     * <p>
     * This allows for the possibility that
     * {@link Reader#read(char[], int, int)} may not read as many characters as
     * requested (most likely because of reaching EOF).
     * 
     * @param input
     *            where to read input from
     * @param buffer
     *            destination
     * @param offset
     *            inital offset into buffer
     * @param length
     *            length to read, must be >= 0
     * 
     * @throws IOException
     *             if there is a problem reading the file
     * @throws IllegalArgumentException
     *             if length is negative
     * @throws EOFException
     *             if the number of characters read was incorrect
     * @since 2.2
     */
    public static void readFully(Reader input, char[] buffer, int offset, int length) throws IOException
    {
        int actual = read(input, buffer, offset, length);
        if (actual != length)
        {
            throw new EOFException("Length to read: " + length + " actual: " + actual);
        }
    }

    /**
     * Read the requested number of characters or fail if there are not enough
     * left.
     * <p>
     * This allows for the possibility that
     * {@link Reader#read(char[], int, int)} may not read as many characters as
     * requested (most likely because of reaching EOF).
     * 
     * @param input
     *            where to read input from
     * @param buffer
     *            destination
     * 
     * @throws IOException
     *             if there is a problem reading the file
     * @throws IllegalArgumentException
     *             if length is negative
     * @throws EOFException
     *             if the number of characters read was incorrect
     * @since 2.2
     */
    public static void readFully(Reader input, char[] buffer) throws IOException
    {
        readFully(input, buffer, 0, buffer.length);
    }

    /**
     * Read the requested number of bytes or fail if there are not enough left.
     * <p>
     * This allows for the possibility that
     * {@link InputStream#read(byte[], int, int)} may not read as many bytes as
     * requested (most likely because of reaching EOF).
     * 
     * @param input
     *            where to read input from
     * @param buffer
     *            destination
     * @param offset
     *            inital offset into buffer
     * @param length
     *            length to read, must be >= 0
     * 
     * @throws IOException
     *             if there is a problem reading the file
     * @throws IllegalArgumentException
     *             if length is negative
     * @throws EOFException
     *             if the number of bytes read was incorrect
     * @since 2.2
     */
    public static void readFully(InputStream input, byte[] buffer, int offset, int length) throws IOException
    {
        int actual = read(input, buffer, offset, length);
        if (actual != length)
        {
            throw new EOFException("Length to read: " + length + " actual: " + actual);
        }
    }

    /**
     * Read the requested number of bytes or fail if there are not enough left.
     * <p>
     * This allows for the possibility that
     * {@link InputStream#read(byte[], int, int)} may not read as many bytes as
     * requested (most likely because of reaching EOF).
     * 
     * @param input
     *            where to read input from
     * @param buffer
     *            destination
     * 
     * @throws IOException
     *             if there is a problem reading the file
     * @throws IllegalArgumentException
     *             if length is negative
     * @throws EOFException
     *             if the number of bytes read was incorrect
     * @since 2.2
     */
    public static void readFully(InputStream input, byte[] buffer) throws IOException
    {
        readFully(input, buffer, 0, buffer.length);
    }

    public static String toString(InputStream input, Charset encoding) throws IOException
    {
        StringWriter writer = new StringWriter();
        IOUtils.copy(input, writer, encoding);
        return writer.toString();
    }
}
